#!/usr/bin/perl -w
use strict;
use IO::Socket;
use IO::Epoll;# qw(:compat);
use Data::Dumper;
my $server = IO::Socket::INET->new(LocalPort => 12345, Type => SOCK_STREAM, Listen => 1) or die $!;
my $poll = epoll_create(10);
epoll_ctl($poll, EPOLL_CTL_ADD, fileno $server, EPOLLIN | EPOLLERR | EPOLLHUP) >= 0
               || die "epoll_ctl: $!\n";
print "fd ".fileno($server)." EPOLLIN ".EPOLLIN." EPOLLERR ".EPOLLERR." EPOLLHUP ".EPOLLHUP."\n";
my @client;
while(1){
        if(my $events = epoll_wait($poll, 10,1000)){
                print "epoll said: ".Data::Dumper->Dump([$events]);
                for my $e (@$events){
                        if ($e->[0] == fileno($server)){
                                #new connection
                                my $client = $server->accept();
                                $client[fileno($client)] = $client;
                                epoll_ctl($poll, EPOLL_CTL_ADD, fileno $client, EPOLLIN | EPOLLERR |EPOLLHUP) >= 0
                                               || die "epoll_ctl client: $!\n";
                        }else{
                                #existing connection
                                if ($e->[1] & EPOLLIN){
                                        my $x = readline($client[$e->[0]]);
                                        print "client ".$e->[0]." said '$x'\n";
                                        if (!defined($x)){
                                                close $client[$e->[0]];
                                        }
                                }else{
                                        warn "polled\n";
                                        print "unexpected event: ".Data::Dumper->Dump([$e]);
                                }
                        }
                }
        }
}

##</code><code>##

fd 3 EPOLLIN 1 EPOLLERR 8 EPOLLHUP 16

epoll said: $VAR1 = [];
epoll said: $VAR1 = [];
epoll said: $VAR1 = [
          [
            '3',
            '1'
          ]
        ];
epoll said: $VAR1 = [];
epoll said: $VAR1 = [
          [
            '5',
            '1'
          ]
        ];
client 5 said 'hello
'
epoll said: $VAR1 = [];
epoll said: $VAR1 = [
          [
            '5',
            '1'
          ]
        ];
Use of uninitialized value in concatenation (.) or string at epoll.pl line 27, <GEN1> line 1.
client 5 said ''
epoll said: $VAR1 = [];
epoll said: $VAR1 = [];